Looking down into Hidden Lake it is hard not to notice the formations decorating the edge of the water. These formations are called shelf stone, unlike the other formations we have seen thus far they are not formed by running water, dripping water. or capillary action but rather by pooled water. In fact, because shelf stone only forms in pooled water it serves as a record of past lake levels in the caves.

As mentioned earlier there are 43 described formations in the Timpanogos cave system, but until recently there were only 42! The most recently recognized speleotheme, Christmas Tree Coral, can be found near Hidden Lake.
This example of Christmas tree coral is very small (less than 1 inch in height) and well hidden under a shelf of rock. No wonder it took so long for someone to notice it! The detail of these formations is really incredible.

Discovering Christmas tree coral in Timpanogos cave reaffirms the need to protect, preserve, and study the entire cave system. There is probably even more neat stuff in the caves just waiting to be discovered!